Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Feb 20 2024 17:19:08 ACUS02 KWNS 201719 SWODY2 SPC AC 201717 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1117 AM CST Tue Feb 20 2024 Valid 211200Z - 221200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE WEDNESDAY EVENING INTO THURSDAY NIGHT ACROSS PARTS OF SOUTHEASTERN KANSAS...NORTHEASTERN OKLAHOMA AND SOUTHWESTERN MISSOURI... ....SUMMARY... A localized area of strong thunderstorm development is possible across parts of the Ozark Plateau and adjacent Great Plains into middle Mississippi Valley vicinity late Wednesday evening into early Thursday, with some risk for severe hail. ....Synopsis... A significant short wave perturbation, splitting away from one stronger branch of westerlies across the northern mid-latitude eastern Pacific, is forecast to contribute to a deepening cyclone while digging southeastward through this period. As it approaches another branch of stronger westerlies across the southern mid- and subtropical latitudes, models indicate that a downstream perturbation within that stream will accelerate inland across southern California and northern Baja by early Wednesday. A rapid east-northeastward progression is then forecast to continue, through the crest of initially more amplified large-scale mid/upper ridging across the central Great Plains into middle Mississippi/Ozark Plateau by 12Z Thursday. At the same time, downstream large-scale mid-level troughing off the southern Atlantic Seaboard appears likely to remain amplified, with some further amplification southward to the east of the Bahamas possible, with continuing cyclogenesis across the western Atlantic. Northerly flow and subsidence in the wake of this regime has contributed to considerable drying across much of the Gulf Basin into Caribbean. While some modification is ongoing across the southwestern Gulf of Mexico through northwestern Gulf coast vicinity, model forecast soundings indicate that boundary-layer moistening will remain rather modest and shallow, beneath warm and capping layers in the lower/mid-troposphere spreading east of the southern Rockies/Mexican Plateau. ....Ozark Plateau/adjacent Great Plains and Mississippi Valley... It does appear that surface low pressure will deepen to the lee of the southern Rockies, northeastward toward the southern Great Lakes region Wednesday through Wednesday night. This likely will be accompanied by strengthening southerly low-level return flow and at least some moistening. However, if, and exactly where, associated large-scale forcing for ascent and destabilization become sufficient to overcome mid-level inhibition remains unclear based on latest model output. Guidance continues to suggest that any thunderstorm development will probably be rooted within the evolving lower/mid-tropospheric warm advection regime across and east-northeast of the Ozark Plateau vicinity late Wednesday evening through early Thursday, though probabilities at any particular location appear low (on the order of 10-20 percent). It might not be out of the question that initial thunderstorm development could be accompanied by some risk for severe hail somewhere across parts of the Ozark Plateau and adjacent Great Plains/middle Mississippi Valley, but this potential stills seems rather conditional at this point. ...Kerr.. 02/20/2024 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .